Referring to FIGS. 1 and 2, a conventional hinge disclosed in Taiwanese Patent No. I441987 (Chinese Patent Certificate No. I696604) includes a leaf mechanism 11 and a torque-providing module 12. The leaf mechanism 11 includes a first leaf 111 fixed to a first object (not shown), a second leaf 112 fixed to a second object (not shown), a plurality of first barrels 113 fixed to the first leaf 111, and a plurality of second barrels 114 fixed to the second leaf 112. The first barrels 113 and the second barrels 114 are disposed in an alternating arrangement and pivoted to each other. The torque-providing module 12 is inserted into the first and second barrels 113, 114, and includes a core axle 121 that is co-rotatable with the first barrels 113, an inner tube 122 that is co-rotatable with the second barrels 114, and a torsion spring 123 that has two opposite end portions respectively fixed to the core axle 121 and the inner tube 122 for providing restoring torque.
When external forces are applied on the conventional hinge to pivot the first and second leaves 111, 112 relative to each other from an initial state, the core axle 121 and the inner tube 122 are driven to deform the torsion spring 123 so as to generate a restoring torque. When the external forces are removed, the restoring torque generated by the torsion spring 123 pivots the first and second leaves 111, 112 relative to each other toward the initial state.
However, a high-speed relative pivotal movement between first and second leaves 111, 112 toward the initial state may cause a severe collision between the first and second objects. On the contrary, if a damping device is employed in the conventional hinge to damp the relative pivotal movement between first and second leaves 111, 112 toward the initial state so as to prevent the severe collision between the first and second objects, the relative pivotal movement of first and second leaves 111, 112 away from the initial state may be considerably retarded.